Code Definition

P013A — Oxygen sensor signal slow to change from Rich to lean - Bank 1 - sensor 2

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P013A

P013A is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P013A is stored, the module has detected a signal or supply voltage lower than the expected operating range; a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine; and a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P013A is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

This fault code is set when the engine control module (ECM) detects that the oxygen (O2) sensor in Bank 1, Sensor 2, is slow to respond when transitioning from a rich to lean condition. This typically indicates that the sensor's ability to respond to changes in the exhaust gas composition is impaired. A slow response could be due to the sensor aging, contamination, or malfunctioning. It might also suggest issues with the exhaust flow or fuel delivery that affect the sensor's readings. Bank 1 Sensor 2 is usually located after the catalytic converter and monitors the efficiency of the converter.

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